Gearwheels, the teeth of which have been produced by cutting, have burrs at their end edges, which have to be removed. The deburring is effected by means of a deburring tool (stripper) or, preferably, on an appropriate generating machine. Since hardened end edges can break off, the end edges are usually not only deburred but also additionally chamfered or bevelled. For this purpose, combined or separate tools for the chamfering and deburring are used on the generating machine.
An apparatus for chamfering the edges at the acute-angled end of the tooth flanks of a helical-tooth gearwheel is known from DE-PS 1627376. This apparatus comprises a guide wheel which engages in the peripherally disposed toothing of the production gear to be deburred. At each of the two sides of the guide wheel there is disposed a chamfering wheel which chamfers the edges of the teeth of the production gear at its face, by cutting and possibly by deformation. Disposed coaxially above each of these chamfering wheels is a cup-shaped deburring wheel which deburrs the production gear at the face, during which material of the production gear, which has been upset on the face during the chamfering of its end edges, is also removed if necessary. The guide wheel and the chamfering wheels are rotatably mounted on a shaft and are connected to one another for joint rotation. The cup-shaped deburring wheels are likewise mounted on this shaft and are pressed against the faces of the production gear by means of cup springs. In this known apparatus, the tool has a complicated and expensive construction consisting of five individual toothed wheels which make a very precise assembly preparation and assembly necessary. The production gear has to be machined twice on each side in order that all sides of the teeth (leading and trailing edges) may be chamfered and deburred. Either the tool has to be reversed, which is time-consuming or a second oppositely identical tool must be used which considerably increases the tool and production costs. Finally, the end edges can only be chamfered but not rounded with this known apparatus.
DE-PS 20 22 937 describes an apparatus for the chamfering or bevelling of the end edges of previously toothed gearwheels without cutting, having a guide toothed wheel which is radially displaceable towards the production gear to be worked, and where the width of the teeth of the guide wheel is smaller than that of the production gear. At each of the two sides of the guide toothed wheel, two end-edge rolling wheels are fitted for joint rotation, abutting against the ends of its teeth. The two end-edge rolling wheels have a greater tooth thickness in transverse section than the guide wheel. With this apparatus, all four end edges of a gearwheel can be chamfered in one operation. Thus deburring and chamfering are effected in the same operating cycle by inclined deformation of the four end edges of each tooth of the production gear. With this known apparatus also, the end edges can be chamfered but not rounded. The tool itself is in three parts and likewise involves heavy assembly expenditure. As in the apparatus first described, the feed movement is effected only radially. It is true that the end edges of the end-edge rolling wheels are adapted to the shape of the chamfer to be produced on the production gear teeth but this can only refer to the chamfer angle because only chamfers on the end edges of the production gear teeth can be produced with this known apparatus. Finally, the storage of this known apparatus is costly because a separate tool has to be made available for each size of production gear, shape of gear teeth etc. Only one size and one type of production gear can ever be worked with one and the same tool.
DE-PS 25 42 372 describes a tool for deburring the flanks of a production gear, which meshes with the production gear and in the course of this forces the material outwards over the end faces of the production gear with a shaping action. It is true that this known tool consists of two discs which are adjustable axially in relation to one another and can therefore be adapted to the size of production gear, but it is not in a position to deburr the end edges of the gear teeth. Separate deburring discs have to be used for the deburring. The concave flanks of the tool for the chamfering and also the deburring discs involve comparatively high production costs and lead to difficulties during the regrinding. To this must be added a limited life.
In a further development of this tool known from DE-PS 28 17 889, a deburring tool for deburring the lateral end faces of the workpiece gearwheel is disposed, in the form of two deburring discs, at each side of the tool gear-wheel and each disc acts with cutting edges on one end face of the production gear. Each deburring disc comprises a continuous circular cutting edge and a chamfer in the region thereof. With this known tool, the adjustment is again only radial and the end edges of the production gear teeth can be chamfered but not rounded. In addition, a separate tool is again necessary for each type and each size of production gear, the tool teeth can easily break off, two tool shafts are necessary (for deburring and chamfering respectively), the tool production is problematical with non-involute-shaped profiles and the tips of the teeth are not chamfered.